A paper supply unit is generally designed to supply paper, and may be applied to or utilized in image forming apparatuses, such as printers, copiers, facsimiles, and the like, to supply paper used in the image forming apparatuses.
A conventional paper supply unit may include a paper supply unit housing having a paper reservoir in which paper is stored. The paper reservoir may include, for example, a knock-up plate on which paper is stacked, a lifting device to vertically move the knock-up plate, a plurality of supporting members to support ends of paper, the supporting members being moveable based on the paper size to allow various sizes of paper to be used in the paper reservoir and a supporting member drive device to move the plurality of supporting members.
The supporting member drive device may be configured to move the supporting members upon receiving an external force applied by a user. The supporting member drive device may include a handle moveable by an external force thus serving to move the supporting members. In such paper supply unit, the supporting members are provided with locking mechanisms to keep the supporting members at predetermined positions while the handle is provided with a lever to selectively release the locking mechanisms upon receiving the external force.
In the above-described conventional paper supply unit, although the lever and handle, to which the external force are applied, are arranged adjacent to an opening of the paper supply unit to allow the user to apply the external force to the lever and handle, the locking mechanisms provided at the supporting members that support an inner end of paper are located deep in the paper supply unit at a significant distance from the opening. Therefore, the locking mechanisms may have a need for a mechanisms to transmit the external force applied to the lever to the locking mechanisms, resulting in a complicated locking configuration. Thus, a paper supply unit with a simplified configuration and convenient operation is desired.